The subject matter disclosed herein generally relates to engine motoring systems, and more specifically to an apparatus and a method for protecting an aircraft engine starter motor from overspeed.
Gas turbine engines used on modern aircraft are composed of a compressor, a combustion chamber, a turbine, and a main shaft connecting the turbine to the compressor. External air is compressed by the compressor and sent to the combustion chamber where an air-gas mixture combusts and provides thrust to the aircraft as it exits the engine. The combusted air-gas mixture also rotates the turbine as it exits the engine and the turbine rotates the compressor through the main shaft. At various times, the main shaft may need to be slowly rotated or motored to maintain thermal equilibrium throughout the engine.